Ask the Fedora maintainer? The README instructions only say Python 3. The OpenSUSE package's specfile only says Python 3, and to be sure I tried installing it and it did not pull in Python 2 packages.

Actually even the Fedora package's specfile only says Python 3, so I'm not sure why the README says that it still needs Python 2.

Edit: Okay, the explanation is in this commit message: https://github.com/boltgolt/howdy/commit/305e42fc79ef38f66c5... . The dep on Python 2 is from Fedora's PAM module package, not from howdy itself. On OpenSUSE the corresponding PAM module package depends on Python 3 already.